(without introducing more risk) Kubernetes without the YAML Puppet Gareth Rushgrove Alternative configuration options for K8

(without introducing more risk) @garethr

(without introducing more risk) Gareth Rushgrove

(without introducing more risk) What we’ll cover This talk

- Why not (only) YAML - A quick look at some alternatives - Short discussion Gareth Rushgrove

(without introducing more risk) The argument Why not (only) YAML

Gareth Rushgrove Brian Grant, Google, Kubernetes Config SIG “We've had a few complaints that YAML is ugly, error prone, hard to read, etc. Are there any other alternatives we might want to support?

(without introducing more risk) Gareth Rushgrove API wire format as user interface template: metadata: labels: app: guestbook tier: frontend spec: containers: - name: php-redis image: gcr.io/google_samples/gb-frontend:v4 resources: requests: cpu: 100m memory: 100Mi env:

The language to represent the data should be a simple, data-only format such as JSON or YAML, and programmatic modification of this data should be done in a real programming language Gareth Rushgrove Borg, Omega, and Kubernetes, ACM Queue, Volume 14, issue 1 http://queue.acm.org/detail.cfm?id=2898444 “

- Avoid repetition - Combine external inputs - Enforce correctness - Introduce abstractions Gareth Rushgrove

(without introducing more risk) Configuration language for JSON data Jsonnet

(without introducing more risk) jsonnet.org

(without introducing more risk) Gareth Rushgrove Jonnet template // Example template { person1: { name: "Alice", welcome: "Hello " + self.name + "!", }, person2: self.person1 { name: "Bob" }, }

(without introducing more risk) Gareth Rushgrove Render templates $ jsonnet example.jsonnet { "person1": { "name": "Alice", "welcome": "Hello Alice!" }, "person2": { "name": "Bob", "welcome": "Hello Bob!" } }

(without introducing more risk) kubernetes examples

(without introducing more risk) kubernetes-anywhere

(without introducing more risk) Gareth Rushgrove Jsonnet functions function(cfg) local if_enabled(addon, manifest) = if cfg.phase3[addon] then manifest local join(arr) = std.foldl(function(a, b) a + b, arr, {}); if_enabled("run_addons", join([ if_enabled("kube_proxy", (import "kube-proxy/kube-proxy.jsonnet" if_enabled("dashboard", (import "dashboard/dashboard.jsonnet")(c if_enabled("heapster", (import "heapster/heapster.jsonnet")(cfg) if_enabled("kube_dns", (import "kube-dns/kube-dns.jsonnet")(cfg) ]))

(without introducing more risk) A REPL for Kubernetes Kubeplay

(without introducing more risk) errordeveloper/kubeplay

(without introducing more risk) Gareth Rushgrove A REPL for Kubernetes $ ./kubeplay kubeplay (namespace="*")> pods # list pods in the cluster kubeplay (namespace="*")> @pod = _.any # pick a random pod from the list kubeplay (namespace="*")> puts @pod.to_json # output the pod definition { "metadata": { ... }, "spec": { ... "containers": [ {

(without introducing more risk) Gareth Rushgrove Ruby based DSL @metadata = replicasets("*/").to_ruby.items.map do |k,v| v.metadata end @metadata.each do |i| puts "Name:\t#{i.name}" puts "Labels:\t#{i.labels}" puts end

(without introducing more risk) Declarative Domain Specific Language Puppet

(without introducing more risk) garethr/garethr-kubernetes

(without introducing more risk) Gareth Rushgrove Puppet DSL kubernetes_pod { 'sample-pod': ensure => present, metadata => { namespace => 'default', }, spec => { containers => [{ name => 'container-name', image => 'nginx', }] }, }

(without introducing more risk) Gareth Rushgrove Query existing resources $ puppet resource kubernetes_pod sample-pod kubernetes_pod { 'sample-pod': ensure => 'present', metadata => { 'creationTimestamp' => '2016-01-20T14:03:23Z', 'name' => 'sample-pod', 'namespace' => 'default', 'resourceVersion' => '4579', 'selfLink' => '/api/v1/namespaces/default/pods/sample-pod’, 'uid' => '91c8a550-bf7e-11e5-816e-42010af001b1' }, spec => { 'containers' => [{ ‘image' => 'nginx',

(without introducing more risk) More Domain Specific Language Terraform

(without introducing more risk) maxmanuylov/terraform-provider-kubernetes

(without introducing more risk) Gareth Rushgrove Terraform provider resource "kubernetes_resource" "mypod" { # Required, must link on the corresponding "kubernetes_cluster" data s cluster = "${data.kubernetes_cluster.main.cluster}" collection = "pods" name = "mypod" labels { a = "b" } }

(without introducing more risk) If you’re interested in this topic One last thing

(without introducing more risk) KubeCon BoF session

(without introducing more risk) Questions? And thanks for listening